1. Field of the invention
The invention is based on a current and voltage transformer for a metal-encapsulated, gas-insulated high-voltage installation having an annular supporting body which can be fixed inside the metal encapsulation and is used for holding a current sensor and a voltage sensor and in which the current sensor, held on the supporting body, is constructed as a toroidally wound coil and the voltage sensor, held on the supporting body, is constructed as a hollow-cylindrical measurement electrode and in which, after fitment in the installation, the coil and measurement electrode concentrically surround a current conductor of the installation.
2. Discussion of Background
In this case, the invention makes reference to a prior art as is provided, for example by DE-Al-2,325,441. A transducer, which is shown in FIG. 1 of this patent publication and is intended for fitment in a metal-encapsulated, gas-insulated switching installation, contains a metallic tube, which is attached in an electrically insulated manner to a mounting projection, and current transformer cores with secondary windings fitted thereon. The metallic tube and the current transformer cores which are supported by said metallic tube and have the secondary windings fitted thereto, are arranged coaxially with respect to a current conductor of the installation, inside the metal encapsulation. The metallic tube forms, with the current conductor, the upper voltage capacitor of a capacitive divider, at whose output a signal is present which corresponds to the voltage on the current conductor. Signals can be picked off on the secondary windings which signals correspond to the current flowing in the current conductor. The current conductor cores have large dimensions and additionally contain predominantly ferromagnetic material, of high specific gravity. Thus the current and voltage transformer according to the prior art is not only very space-consuming but should additionally be of particularly robust construction, because of its high weight.